Search results for "Computer Networks and Communication"

A non-supervised approach to locate and to measure the nuchal translucency by means of wavelet analysis and neural networks

2017

Ultrasound imaging is a well known noninvasive way to evaluate various diseases during the prenatal age. In particular, the thickness measure of the nuchal transucency is strictly correlated with pathologies like trisomy 13, 18 and 21. For a correct investigation, the methodology needs mid-sagittal sections and the proposed approach is based on wavelet analysis and neural network classifiers to locate components useful to identify mid-sagittal planes. To evaluate the performance and the robustness of the methodology, real clinical ultrasound images were considered, obtaining an average error of at most 0.3 millimeters in 97.4% of the cases.

Robust fault tolerant tracking controller design for a VTOL aircraft

2013

This paper deals with the fault tolerant control (FTC) design for a Vertical Takeoff and Landing (VTOL) aircraft subject to external disturbances and actuator faults. The aim is to synthesize a fault tolerant controller ensuring trajectory tracking for the nonlinear uncertain system represented by a Takagi-Sugeno (T-S) model. In order to design the FTC law, a proportional integral observer (PIO) is adopted which estimate both of the faults and the faulty system states. Based on the Lyapunov theory and ℓ2 optimization, the trajectory tracking performance and the stability of the closed loop system are analyzed. Sufficient conditions are obtained in terms of linear matrix inequalities (LMI). …

Robust l2-gain control for 2D nonlinear stochastic systems with time-varying delays and actuator saturation

2013

Abstract This paper is concerned with the problems of stability analysis and l2-gain control for a class of two-dimensional (2D) nonlinear stochastic systems with time-varying delays and actuator saturation. Firstly, a convex hull representation is used to describe the saturation behavior, and a sufficient condition for the existence of mean-square exponential stability of the considered system is derived. Then, a state feedback controller which guarantees the resulting closed-loop system to be mean-square exponentially stable with l2-gain performance is proposed, and an optimization procedure to maximize the estimation of domain of attraction is also given. All the obtained results are for…

How and when do mobile media demands impact well-being? Explicating the integrative model of mobile media use and need experiences (IM3UNE)

2021

Using mobile media can be both detrimental and beneficial for well-being. Thus, explaining how and when they elicit such effects is of crucial importance. To explicate boundary conditions and processes for digital well-being, this article introduces the Integrative Model of Mobile Media Use and Need Experiences (IM³UNE). Instead of assuming mobile media to be pathogenic, the IM³UNE offers a salutogenic perspective—it focuses on how we can stay healthy when using mobile media ubiquitously in daily life. More specifically, the model assumes that both the satisfaction and the frustration of basic psychological needs are key underlying mechanisms linking demanding mobile media use to well-being…

Unauthorized copying of software and levels of moral development: a literature analysis and its implications for research and practice

2004

.  Several approaches for and against the unauthorized copying of software have been proposed. These approaches can be divided into two categories: moral reasoning and solution. These categories of approaches to unauthorized copying of software are scrutinized in the light of Kohlberg's theory of Cognitive Moral Development. The results suggest that most approaches presenting solutions to unauthorized copying of software have focused attention on the lower levels of moral development, while approaches at the highest stage are few and far between. No single approach covers all the stages of moral development. The implications of this analysis for practice and research are discussed.

Automated Synthesis of Application-layer Connectors from Automata-based Specifications

2019

Abstract Ubiquitous and Pervasive Computing, and the Internet of Things, promote dynamic interaction among heterogeneous systems. To achieve this vision, interoperability among heterogeneous systems represents a key enabler, and mediators are often built to solve protocol mismatches. Many approaches propose the synthesis of mediators. Unfortunately, a rigorous characterization of the concept of interoperability is still lacking, hence making hard to assess their applicability and soundness. In this paper, we provide a framework for the synthesis of mediators that allows us to: (i) characterize the conditions for the mediator existence and correctness; and (ii) establish the applicability bo…

High performance hardware correlation coefficient assessment using programmable logic for ECG signals

2003

Abstract Correlation coefficient is frequently used to obtain cardiac rhythm by peak estimation and appreciate differences in the signal compared to a pattern. This work focuses on the description of a real-time correlation assessment procedure. Applied to electrocardiogram (ECG) signals, a new correlation value is obtained every new sample and pulse detection information is provided. The ECG pattern is internally stored and can be changed when desired. This procedure is useful in Systems on Chip implementation and can be applied to design compact ECG monitoring systems consisting on a system on chip where programmable logic offloads the main processor. A Xilinx FPGA device has been used fo…

Tracing the Cultural Background of Lone-Wolf Terrorism

2021

The end of the Cold War, as well as the collapse of the Soviet Union, posed new greater challenges and risks for the “Global North.” Terrorism—doubtless—seems to be one of them. Over the recent years, and particularly after 9/11, terrorists changed the focus of their attacks. While classic terrorism targeted important persons such as politicians, chief police officers, or celebrities, modern terrorism planned attacks on leisure-spots spaces, tourist destinations, and lay-persons. This is particularly troublesome for policymakers (who are in charge of orchestrating all-pervading models to preserve homeland security) and for field-workers who are seriously punished when they are in contact wi…

2020

Abstract Information technology (IT) engagement is defined as a need to spend more time using IT. Practice-based examples show that IT engagement can have adverse effects in organizations. Although users can potentially get more work done through IT engagement, observations show that the users might jeopardize their well-being and hamper their work performance. We aimed to investigate this complexity in the research on IT engagement by examining its potential antecedents and outcomes in organizations. Considering the potentially mixed outcomes, we developed a model to examine the effects of IT engagement on personal productivity and strain. We also aimed to explain the antecedents of IT eng…

Consumers' perceptions of mobile banking continuous usage in Finland and South Africa

2015

This study examines continuous usage behaviour related to mobile banking (m-banking) among consumers living in Finland (FI) and South Africa (ZA). The study investigates three post-adoption behavioural consequences - namely, trust, satisfaction and word of mouth. Using purposeful sampling techniques, we found that trust plays a significant role in promoting continuous usage of m-banking. In general, the respondents reported high levels of trust in m-banking technology and were satisfied with the m-banking application and services. In addition, convenience, user friendliness and speed emerged as the main sub-topics related to satisfaction. In most cases, the convenience of using m-banking do…